We found that after the upgrade to 4.0 the wiki-markup editor and all offline-edit functionality was removed. But I noticed, that there is a bug in the conversion process. Macros with capitals do not get converted. They are covered by a special wiki-markup macro. Though being displayed correctly you can see that when going to the edit-mode (see atteched screenshot).
When it is possible to enter that wiki-markup macro and e.g. have an optional parameter, that keeps it from converting it's content to the new format, the old markup-editor is back and also the offline-edit functionality since the markup code can easily (copy and paste) be taken to some other editor and being edited while offline.